I'm looking into getting a 100 f/2.8L or 135mm f/2L, to do some portrait/ macro work. I won't be using the Macro a ton, but would like the feature. As of today, my budget only allows for one or the other, so I could use your help in deciding between the two.

Right now, I'm using a 24-70 f/2.8L Mark I, and a 50mm 1.4 on a 50D Body.

Recommendations?

The 135L is the best portrait lens for the money. You can get pretty close for light macro work with extension tubes if you really want.

I have the good fortune owning both lens, and I will confess that there is some overlap. I would definitely agree that the 100L is the more flexible tool, particularly if you are shooting a crop body only. In fact, if you only plan to shoot crop bodies, I think the 100L wins hands down.

If you are shooting FF, however, the 135L produces the finest images this side of the $6000 200 f/2L IS. I bought it because I realized that my favorite shots from others were almost always with it. If you are shooting environmental portraits, it is a sublime instrument. I have shot portrait sessions in terrible light and ended up with gorgeous results. It has amazing delineation of your subject from the setting, and the transition to ooF area is incredibly smooth. I use it a LOT in event work like weddings/business events, and it never fails to transform something mundane into something far more special. I also use the 100L at event work, and it is also great. But the 135L is something just a little more special.

Jesse said the 100L is a better value portrait lens. I would agree only if you are talking crop format only. If you are talking full frame, the 135L is arguably the best portrait lens in existence.

""real" macro near 1:1 mag is when your lens cap nearly hits the object,"You actually have a lot of workspace when shooting with the 100L. Your lens never nearly hits the object even at minimum focus....

That's why I said "nearly" ... I just checked it, on my 60d the space between cap and object is about 2cm, I wouldn't really call this a lot of workspace ... but ymmv :->

After playing with the 135mm I decided to return it. It is truly effin long, even on full frame, and I can't hold steady any longer time than 1/50s, even that is a hit or miss. Compared to the 100L with IS this is really useless, I'd rather use the 100L in dim light situations although it is one stop more closed but I can hold 1/15 to 1/10s without problems with the IS activated.

Despite the magical bokeh the 135 achieves, the 100L is sure the better and more universal choice because of macro and IS.

I agree with several here that 135 on a crop body is a bit long indoors. My wife uses my 135 often on her 600D, but mostly outdoors. However... If you go for the 100L (which is also a great lens), you not only give up a stop, but also speed on the AF. The 135 is very fast in AF. Second, I would also think about another point, which is that when you are about to invest in L glass as you are now, I would also think past your current camera. Don't know if you are thinking about going full frame or not, but if you see yourself going that way, I would argue that the 135 is the third best portrait lens in the Canon lineup (200 F2.0L, 85L II, 135L). A great lens will outlast a body..

For me the difference between 100L and 135L is just too small to own them both. Either have 2.0 with perfect bokeh, but no IS, or have 2.8 with still great bokeh, IS and macro. For me the IS is quite the biggest deal here thus I stay with the 100L.

If you can afford both, sure, hit it up. I can't respectively spend it on other lenses.

They're are very, very close in producing great photos. So close I consider them Equal.

I have the 135 and love it, and I am borrowing the 200 F2.0L for an indefinite timespan (a bit big to carry around, but great). I have borrowed the 85L II several times, and it has left me wanting. I am no expert to be able to speak with umph on which is best, but my impression is that the latter has an extra thing to it.

I'm looking into getting a 100 f/2.8L or 135mm f/2L, to do some portrait/ macro work. I won't be using the Macro a ton, but would like the feature. As of today, my budget only allows for one or the other, so I could use your help in deciding between the two.

Right now, I'm using a 24-70 f/2.8L Mark I, and a 50mm 1.4 on a 50D Body.

Recommendations?

jman....it definitely depends on whether you will be shooting indoors or outdoors. for indoor shooting of portraits on your crop body, even the 100 is a bit long. the 135 for indoors is way too long...go over to a local camera store and put a zoom (or the 135 if they have it) lens on a crop body at 135mm and take a few shots to see for yourself.